Longevity of Radopholus Similis (Cobb) in Host-Free Soil

Abstract

Burrowing nematodes do not survive more than six months in sandy soils in Central Florida (U.S.A.) in the absence of suscept roots. Populations in citrus roots and soil contained in cheesecloth, nylon, or polyethylene bags buried at depths of 31-152 cm disappeared within six months, whereas Hoplolaimus coronatus, Pratylenchus brachyurus, and numerous saprobic species survived under these conditions. Polyethylene was not toxic to burrowing nematodes, and was impenetrable to this species in greenhouse tests. Living uninfected or infected citrus roots in the vicinity of buried polyethylene bags of infested roots and soil had no effect in prolonging the longevity of the Radopholus contained in those bags. Burrowing nematodes in soil and roots enclosed in polyethylene failed to survive when stored six months at an average laboratory temperature of 24.4° C. and an average refrigerator temperature of 1.1° C. Additional bags of infested material placed in gallon cans of autoclaved soil and held six months at an average greenhouse temperature of 24.9° C. likewise failed to yield burrowing nematodes when the cans were either kept dry, maintained at field capacity, or placed on an alternating cycle from field capacity to dry conditions.